1. Field Of The Invention
The invention relates to a device for applying a descaling agent to the inner surface of a red-hot hollow billet in the production of seamless tubes as well as to a process in which the device is used.
2. Background Art
A process for descaling the inner surface of red-hot hollow billets in the production of a seamless tube and a device for carrying out such process are known (see European Published Patent Application No. 0133937). In such process and with such device, the carrier gas stream, laden with a material, namely, a descaling agent, is conducted with the swirl directly through the hollow body, namely, the red-hot hollow billet. By means of the swirl, whereby a more uniform distribution of the material in the carrier gas occurs, and of the centrifugal force occurring as a result of the swirl, a considerable part of the material is brought to the inner surface of the hollow body without following the force of gravity.
The laden carrier gas stream with the swirl must first force the static air in the hollow space through and out of it. In this case, a part of the swirl is transferred to such air and is lost for applying the material to the inner surface of the hollow body. If the laden carrier gas stream flows through the hollow space, its speed and swirl close to the inner surface are less than in the middle of the hollow space cross section. The flow becomes laminar because of the fraction on the inner surface, especially if it is scale-pitted, i.e., in the case of a hollow billet coated with a layer of scale. On the whole only a part of the swirl imparted to the laden carrier gas stream is effective in applying the material to the inner surface.